[Chromoting] Fix jscompiler warning

remoting/webapp/butter_bar.js

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview
  * ButterBar class that is used to show the butter bar with various
  * notifications.
  */
 
@@ skipping 22 matching lines @@
       [remoting.ButterBar.kSurveyStorageKey_,
        remoting.ButterBar.kHangoutsStorageKey_],
       onSyncDataLoaded);
 }
 
 /**
  * Shows butter bar with the specified |message| and updates |storageKey| after
  * the bar is dismissed.
  *
  * @param {string} messageId
- * @param {string} substitutions
+ * @param {string|Array} substitutions
  * @param {string} storageKey
  * @private
  */
 remoting.ButterBar.prototype.show_ =
     function(messageId, substitutions, storageKey) {
   this.storageKey_ = storageKey;
 
   var messageElement = document.getElementById(remoting.ButterBar.kMessageId_);
   l10n.localizeElementFromTag(messageElement, messageId, substitutions, true);
   var acceptLink =
@@ skipping 73 matching lines @@
   var value = {};
   value[this.storageKey_] = {
     optIn: accepted,
     date: new Date(),
     version: chrome.runtime.getManifest().version
   };
   chrome.storage.sync.set(value);
 
   document.getElementById(remoting.ButterBar.kId_).hidden = true;
 };